The invention relates to an apparatus and method for directly depositing a submicron thin film pattern onto a substrate.
Methods for depositing integrated circuit patterns on a substrate invariably include a series of successive steps involving a photoresist layer on the substrate. One such method is the standard "liftoff" photolithography technique. This technique involves the preparation of a photoresist layer on the substrate by masking the photoresist layer, exposing the photoresist to light, and removing the exposed photoresist by developing. A source of metal can then be evaporated onto the photoresist, after which the photoresist layer is removed to leave the desired circuit pattern on the substrate. Other methods are the electron and ion beam techniques. In the electron beam technique an electron beam is moved according to a computer generated pattern so as to literally write on the photoresist layer a desired circuit pattern. The photoresist layer is then developed to remove the exposed regions and metal is deposited on the substrate. This method has three disadvantages, namely: (1) a considerable amount of time is required to implement the method, (2) it is hard to produce small patterns on the substrate, and (3) the edges of the pattern are rough. The ion beam technique ionizes a gas, such as Argon, and the positive ions thereof are utilized to bombard a previously prepared photoresist on an aluminum layer on a substrate. The ions will etch away the aluminum without effecting the photoresist. The photoresist is then removed to leave a pattern of aluminum which is normally quite sharp in detail. All of the aforementioned techniques involve intermediate steps which are time consuming.